Lightning Ridge Technologies, working in collaboration with The Innovation Laboratory, Inc., extend Automatic Dependent SurveillanceÂ? Broadcast (ADS-B) into a safe, secure, authenticated system. Historically, ADS-B has been criticized for its inability to guarantee safe and secure surveillance in all operational conditions. The technology presented in this proposal provides an integrity check on all ADS-B data that is independent of all primary surveillance modes and is 100% robust to all GPS spoofing attacks. An important by-product of that integrity check provides us with the further ability to do aircraft-to-aircraft relative positioning that is more accurate and more reliable than any civilian system in existencetoday. The ADS-B integrity check and the aircraft-to-aircraft positioning can provide a further basis on which to enhance the safety of the National Airspace System (NAS).